The Fermi Paradox - Rare Earth Hypothesis Part 1

I think I'm seeing some failure to understand a few things, and that's okay because some of them have not been covered yet.

First, as stated in the OP, not all the stars in a galaxy are going to be good candidates:

1) Stars that are too close to the core of the galaxy.
2) Stars that are too far out that are too old (IE low metal content).
3) Stars that are too massive that are too short lived (life spans not long enough for life to develop on planets that orbit them).
4) Stars that are not stable and put out way too many solar flares and solar radiation.

So saying "due to the massive amounts of stars, it HAS to be true" is not true. Many of them can't be used. It would be like looking at a freeway full of cars and saying that because there are so many cars on the freeway, everyone in the world must own one.

Age of the universe is another one used, and a subject we've not covered yet. But the fallacy is: because the universe is 14 billion years old, that means there has been plenty of time for advanced civilizations out there to form.

Not true. There were not enough heavy elements at the beginning of the universe. You had to have the Population 3 stars form first and you needed them to start fusing atoms into heavy elements.

That took a LOT of stars and a LONG time to do. Billions of years, to where we didn't start getting stars with enough metals in them (so that you'd get planets with enough metals in them also) forming until about 8 billion years ago.

So you do not have that full 14 billion years. Any rocky planets that finally first formed way back then would have been very, very metal poor. Not enough for a species to become a very advanced civilization.

Just looking at a galaxy that has 200 billion stars does not mean you're going to have billions of advanced civilizations there.

The only thing it means for sure is that it has 200 billion stars. You have to break them down after that to try and find what is a closer truth of how many might have planets that can support life that can develop into a advanced civilization. There are many things that can interfere with it as I listed above, and then even more things we've not talked about.

For example, just take a look at our own planet here: how many species of life have come about here on Earth? It's a very, very, very large number.

Now how many of them have become tool using and advanced enough with technology to not only send signals out into space, but space craft too?

One. One out of how many billions of animal species that evolved right here on Earth?

It's the same parallel with looking at a galaxy with hundreds of billions of stars.

Very interesting thread.
S& F
I find what , in my mind is a sticking point for many scenarios. Time.
We think in our own time references. 120 years is a normal human life span. Our science tells us that there's really no reason for this, it just is. But what if a race averaged 4 times that ?
(A small mutation to a gene early in their evolutionary development. )What could an Issac Newton or an Einstein accomplish in such a span ?

We don't know how fast civilizations can grow. We don't know how many setbacks we had early on , or if other alien species had less or more of these setbacks. Projecting the process of intelligence of our species onto all others is a needless contortion because there is no baseline.

But we can be sure that on the whole, life finds ways to prosper. (Deep sea sulphur vents are an example.) The building blocks of life are spread across the heavens , and it seems that wherever life gets a foothold,it finds a purpose in growing and changing.
IMO , intelligence is a continuum. Something smarter is always coming along to replace the status quo. Brainpower is an arms race , always has been , even across species.
The "Rare Earth" idea seems like whistling in the cemetery. Alien contact is fraught with danger, but trying to convince ourselves it can't happen because we're scared won't help.

VF

a reply to: eriktheawful

You human aliens are the last race of breathing aliens in the entire galaxy. Aliens from other planets don't exist until you as humans go to other planets and evolve later in time as to what you will evolve to.

Noah's ark is a story on how you aliens, the real and last aliens where bought here to this earth.
All the planets in your study's conclude one fact,they were all inhabitable at some point in time.

How many civilizations, species ,and aliens do you really think survived in the last 500 years, let's try 10,000 years, 1million, what about 100 billion.

You ever wondered why as a baby,so many vaccination are needed?You ever wonder why people get darker from the sun cancer and such, because humans are not originally from earth.

Animals are originally from this earth that's why they never die by viruses or diseases unless us aliens have giving it to them.

You all are the last intelligent aliens, the alpha the new beginning,in this entire galaxy and beyond.

Over 100 billion years plus of civilizations and species have come and gone, you mortals have to live with the fact that,your the alpha and the Onega.

You want to see intelligent aliens look in the mirror and look up in the sky and look at the last and only sphere that sustains life in all galaxies.

I think the seven requirements are pretty reasonable except for one key condition. That is that the sort of life we are talking about is extremely Earth-like. Merely making the distinction that life is intelligent and capable of using tools does not go far enough in my opinion. With that clarification in mind, even if we were to be strict with the odds of less than one potential target per galaxy, given the number of known galaxies out there, it's still almost a certainty we are not alone. So discussing whether or not we are alone seems pointless. Of course we are not.

However, the question of why these other Earth-like brothers and sisters are difficult to bump into is a far more worthwhile one. Many good reasons why have already been raised, but one that may not have been considered, is human-nature. Based on our own society's eagerness to act in self interest more often than the interest of the community at large coupled with the arrogance to repeatedly assume we know everything, one must assume that the same personality flaws afflict life on other worlds too, and therefore is probably stifling their efforts to reach out to other worlds, in a similar fashion to how our own efforts are being stifled.

originally posted by: ImmortalLegend527
a reply to: eriktheawful

You human aliens are the last race of breathing aliens in the entire galaxy. Aliens from other planets don't exist until you as humans go to other planets and evolve later in time as to what you will evolve to.

Noah's ark is a story on how you aliens, the real and last aliens where bought here to this earth.
All the planets in your study's conclude one fact,they were all inhabitable at some point in time.

How many civilizations, species ,and aliens do you really think survived in the last 500 years, let's try 10,000 years, 1million, what about 100 billion.

You ever wondered why as a baby,so many vaccination are needed?You ever wonder why people get darker from the sun cancer and such, because humans are not originally from earth.

Animals are originally from this earth that's why they never die by viruses or diseases unless us aliens have giving it to them.

You all are the last intelligent aliens, the alpha the new beginning,in this entire galaxy and beyond.

Over 100 billion years plus of civilizations and species have come and gone, you mortals have to live with the fact that,your the alpha and the Onega.

You want to see intelligent aliens look in the mirror and look up in the sky and look at the last and only sphere that sustains life in all galaxies.

Then why does are genome match every animal on the planet. Even a dolphin shares about 89 percent of our DNA. Mice 90 percent dogs 84 percent. And our closest relatives chimpanzees 99.4 percent for not being from this planet we sure do seem to share a lot with the life here on this planet.

Odd almost like millions if years of evolution formed us and the life on this planet.

a reply to: schuyler

Excellent and thoughtful response. The circumstances that allowed for us to be here now were arguably created by blind luck. It's been one improbability stacked on another to get past the most basic of life-forms. That's without even mentioning the role of our planetary neighbours in sweeping up the debris of space.

Imagine what we would be like without a Moon? I don't mean in terms of tides either. What effect might it have had on our technological progress? We wouldn't have had a space race, but neither would the sciences of astronomy and astrophysics have been the same. Our Moon has been a gift to inspiration and a incentive for explorers and scientists alike.

Rare indeed.

To think they could pick up our radio signals is, I think, a fanciful idea. We've gone digital in about 100 years, and radio waves dissipate. Nobody else is going to get a recognizable signal from us, the movie "Contact" notwithstanding. So given that context, it is obvious why "they aren't here." Even if they are contemporary to us, they don't know we are here at all.

I wrote in another thread about 'street light effect' and I think it applies with our historical search for radio signals. We looked for what we knew until better methods came along and increased the glow from our metaphorical street light.

In future, science will be searching for signature signs of life in the atmospheres of distant worlds. The James Webb Space Telescope will begin to do this with some exoplanets in the next couple of years. It's exciting stuff and I hope they move on to studying watery, Earth-like planets in both of our lifetimes. Looking for oxygen, ozone and methane will be infant steps, but they'll eventually be looking for such things as pollutants created by manufacturing metals.

What I like about this approach is how it offers way bigger timelines within which to identify technological life. As you pointed out, radio signals are very small windows (timewise) indeed. For the sake of argument, our own biosignatures will have been visible for millions of years and our artificial pollutants for more than ten thousand years. Imagine that? Our Industrial Revolution could be a subject to study on a world some fifty to a hundred light years away.

At the very least, we'll be shining more light on the 'Earths' out there and getting a much better perspective on what 'rare' actually means.

originally posted by: eriktheawful

Just looking at a galaxy that has 200 billion stars does not mean you're going to have billions of advanced civilizations there.

The only thing it means for sure is that it has 200 billion stars. You have to break them down after that to try and find what is a closer truth of how many might have planets that can support life that can develop into a advanced civilization. There are many things that can interfere with it as I listed above, and then even more things we've not talked about.

Right I get this point. My point is that even if out of every 100 galaxies there is just ONE star that has a planet that can support life, that still leaves MILLIONS of stars with planets that might have advanced life on it.

Hubble reveals an estimated 100 billion galaxies in the universe or so, but this number is likely to increase to about 200 billion as telescope technology in space improves

I could be wrong, I just tend to think that life is not as rare as we believe due to the sheer vastness of the observable universe. I also don't think that life has to advance the same way it has here.

So many possibilities, Star Wars could be a true story

Solutions like Rare Earth can be a hard pill to swallow, after all, as many pointed out, the sheer number of stars and galaxies tend to make people feel like it can't be that rare, and can be shocking to find out that there ends up being a lot of conditions.

Part two of Rare Earth discusses how likely intelligent life is to evolve by looking how it came about here on Earth (because....it's the only example we have to go by).

However, I think before we go to that one, I'm going to go ahead and do one that I think people will have a LOT more fun with: Communication.

That one tends to make people feel better because it assumes that yes, there are lots of intelligent aliens out there for the most part, and concentrates on why we might not "hear" them, or they hearing us. Most people tend to like this discussion, and it can get a lot more speculative too.

Working on that one today.

a reply to: For the sake of argument, our own biosignatures will have been visible for millions of years and our artificial pollutants for more than ten thousand years. Imagine that? Our Industrial Revolution could be a subject to study on a world some fifty to a hundred light years away. Kandinsky

thats better then my opinion on sattelites that could detect nuclear explosions far far away.

One thing is important. Life leave markers that can be recognized.. From us AND they..

Its just a matter of time..

Loving this threads. Thanks erik! star n flag

a reply to: yorkshirelad

And what if you only visited solar systems with planets you know are in the habitable zone?

originally posted by: ImmortalLegend527
a reply to: eriktheawful

You ever wondered why as a baby,so many vaccination are needed?You ever wonder why people get darker from the sun cancer and such, because humans are not originally from earth.

Yes, humans ARE from this Earth. You have no evidence at all that we are not and there is a massive amount of evidence that we are. Further, you are not addressing the issue. The question is the Fermi Paradox: "Why aren't they here?" THIS thread deals with ONE possible answer to that question: "Because Earth is rare." Your posts certainly present your point of view. It's unsupportable, but the most important point is that it is off-topic for this thread. It's not what we are talking about. Focus on the issue.

originally posted by: OccamsRazor04
a reply to: yorkshirelad

And what if you only visited solar systems with planets you know are in the habitable zone?

Seems to me that would be the proper way to do it. You don't really want to waste resources visiting systems that have only gas giants, for example. That certainly narrows your choices, but a Goldilocks Zone does not guarantee a Sentient Civilization. Look at our efforts in this regard. Our "reach" is measured in the hundreds of light years, not millions. The amount of space and the number of systems we can see in our attempt to find planets is very, very small. If "the Earth is rare," the chances of our finding another one are also. So it would be the same for anyone else looking for the likes of us.

a reply to: ImmortalLegend527

Actually that is evidence humans ARE from Earth. Why would a virus evolve to target humans if humans are not from Earth? Melanin protects us from the sun, which is why exposure "tans" us. Why would be evolve to do that if we are not from Earth?

Thanks for highlighting strong evidences of human origins being Earth.

a reply to: schuyler

Yes, but we are just starting the search and not even close to 24 hour FTL travel to any solar system we want to visit. When that tech was developed I would think the candidates to search would be narrowed down in regards to where to look and broadened as far as how far out to look.

originally posted by: OccamsRazor04
a reply to: schuyler

Yes, but we are just starting the search and not even close to 24 hour FTL travel to any solar system we want to visit. When that tech was developed I would think the candidates to search would be narrowed down in regards to where to look and broadened as far as how far out to look.

OK, but "they aren't here." So that has not happened. And as far as we know, FTL travel is impossible (which is fodder for another thread in this series, I think.)

originally posted by: schuyler

originally posted by: OccamsRazor04
a reply to: schuyler

Yes, but we are just starting the search and not even close to 24 hour FTL travel to any solar system we want to visit. When that tech was developed I would think the candidates to search would be narrowed down in regards to where to look and broadened as far as how far out to look.

OK, but "they aren't here." So that has not happened. And as far as we know, FTL travel is impossible (which is fodder for another thread in this series, I think.)

I agree, and also agree we are drifting OT .. merely saying in the "what if" scenario that person presented, the task would not be so daunting as they claimed in the scenario they created (which we both agree does not match reality as we know it).

originally posted by: dragonridr

originally posted by: ImmortalLegend527
a reply to: eriktheawful

You human aliens are the last race of breathing aliens in the entire galaxy. Aliens from other planets don't exist until you as humans go to other planets and evolve later in time as to what you will evolve to.

Noah's ark is a story on how you aliens, the real and last aliens where bought here to this earth.
All the planets in your study's conclude one fact,they were all inhabitable at some point in time.

How many civilizations, species ,and aliens do you really think survived in the last 500 years, let's try 10,000 years, 1million, what about 100 billion.

You ever wondered why as a baby,so many vaccination are needed?You ever wonder why people get darker from the sun cancer and such, because humans are not originally from earth.

Animals are originally from this earth that's why they never die by viruses or diseases unless us aliens have giving it to them.

You all are the last intelligent aliens, the alpha the new beginning,in this entire galaxy and beyond.

Over 100 billion years plus of civilizations and species have come and gone, you mortals have to live with the fact that,your the alpha and the Onega.

You want to see intelligent aliens look in the mirror and look up in the sky and look at the last and only sphere that sustains life in all galaxies.

Then why does are genome match every animal on the planet. Even a dolphin shares about 89 percent of our DNA. Mice 90 percent dogs 84 percent. And our closest relatives chimpanzees 99.4 percent for not being from this planet we sure do seem to share a lot with the life here on this planet.

Odd almost like millions if years of evolution formed us and the life on this planet.

Because you evolved with them,you humans grew up with them.

Animals can naturally adapt to any planet, animals can live for a very long time on planets because planets and animals are made for each other. Planets and animals are naturally balanced to help each other to keep the planet evolving.

The balance of you particular aliens are not balanced to evolve on this particular planet because of the destruction virus's and diseases that you aliens have bestowed on this planet,you humans just don't fit the regular balance of a regular evolution.

All humans of race on this planet are from different planets from a very long time ago.

For every language spoken there is a planet that shares a story.Humans were dropped off in Africa when the planet was a giant pie,before the continent's separated.
Homo sapiens and you the aliens have nothing in common as far as evolution,they was here first and you were dropped off last.

The diseases and viruses that you aliens bought to this earth is proof that you don't belong here.
Your technology is proof that you are the last breed of intelligent life. Really not understanding why, would humans think that Thiers anything more intelligent out there than them.

Guys.. cool down and get back to topic

Its immortals opinion.. we dont know where we (humans) are from. All we know is that we share 95% of dna with chimpanzee's AND that we are on this rare blue marble..
As long as no one can explain the missing link everything is just speculation.

What has the earth and humans in common? Both are rare cause we dont know any other tool and machine using intelligent lifeform